Ingot mold and stool therefor



Nov. 1, 1927.

1,647,660 J. E. PERRY' v INGOT MOLD AND STOOL THEREFQR Filed Jan. 21, 1926 '2 Sheets-Sheet 1 INVENTOR rm Nov. 1, 1927. 1,647,660 A J. a. PERRY 4 INGOT MOLD AND STOOL THEREFOR ild Jan. 21. 1926 2 Sheets-Shoot 2 INVENTOR fiimlilerry BY I ::::.:;fi m

Patented Nov. l, 1927.

NITED STATES JOHN E. PERRY, or SHARON, PENNSYLVANIA.

INGOT MOLD AND STOOL THEREFOR.

Application filed January 21, 1926. Serial No. 82,635.

This invention relates tometallurgy and especially to mold structuresmore particularly adapted for the production of steel 1ngots and the like.

5 This invention comprises novel features in the mold, novel features in the stool, and

also the combined novelty of the stool and the mold in'their assembled relation ready to receive molten steel or the like.

The objects .of the invention will be apparent from an understanding of the structures, preferred forms of which will be more specifically described in the specification following by reference to the accompanylng 1o drawings forming a part of this application.

Realizing that the present invention may be embodied in structures other than those disclosed herein, it is to be understood that the said disclosure is illustrative and not to be considered in the limiting sense.

Heretofore in the art it has been customary to use ingot molds comprising a tubular structure usually tapered, and with the said molds adapted to be set upon fiat casting bottoms referred to as stools. Difficulties are numerous in connectionwith this type of construction in that the stooltends to burn out from beneath the mold and often forms cavities that produce fins, bumps, or

protuberances on the ingot which overlap the end of the mold and interfere with subsequent operations such as stripping, rolling, etc., and produce steel of inferior quality in the ingot itself.

These difiiculties are ,magnified where molds of the big-end-up type are used, in that any tendency to form a fin or interlocking portion between the ingot and the mold structure at the bottom of the mold produces defects in the steel ingot cast in such mold. For example, where a big-end-up mold is used and a fin or bump occurs at the bottom of the set-up, when this portion of the steel freezes or solidifies it firmly anchors the bottom of the ingot to the bottom. of the mold so that when the mold is filled with steel and it freezes the taper of the bigendup mold tends to prevent a downward movement of the upper part of the ingot and the frozen interlock lower part tends to prevent upward movement of the lower part of the ingot so that during the freezing operation the ingot literally pulls itself apart, thus forming cracks, and bad steel structure in the ingot is thereby the result.

The present invention overcomes many difiiculties in the known prior art by providing a mold and a stool so constructed as to form a tight metal to metal joint adjacent the bottom of the mold, consequently obviating any formation of fins or other protuberances tending to interlock'the ingot and the mold. The invention is useful with either big-end-down or big-end-up type of molds. It comprises the further thought of providing a construction whereby the mold and stool are formed with mutual guides insuch manner that when the crane is operated to set the mold on the stool, the mold automatically assumes a definite fixed relation to the stool. This enables the stool to be provided with a. relatively small joint surface which may be accurately formed in any practical manner. Preferably, this surface on the stool is obtained by casting the stool against a chill plate, which has the further advantage of hardening the upper surface of the stool and thereby increasing the ability of the stool to withstand cutting effects from the hotsteel poured into the setup. The accurate positioning of the mold upon the stool is particularly desirable where the cross-section of the mold is rectangular, or of a geometric shape other than circular, in that it permits a definite relation to be automatically maintained between the matrix surface on the stool and the matrix of the mold.

Having generally described the invention, the specific preferred embodiments disclosed in the drawings are designated by like characters throughout the several fi ures thereof. It is to be understood that t e mold and the stool may be cast from cast iron, or other materials well known in the art.

Fig. 1 illustratesa portion of a mold and a stool in cross-section showing wedge-like guides on the stool and cooperating lugs on the mold.

Fig. 2 is a plan view of the construction illustrated in Fig. 1 and showing the mold in cross-section.

i 3 is a cross-sectional view of the bottom of a mold and of a stool whereby the mold is guided by the lower portions thereof without the use of lugs on the mold.

- Fig. 4 is a detailed view of the bottom of a mold and a stool, in cross-section, provided with four interlocking guiding devices.

Fig. 5 is a plan view of the stool illustrated in Fig. l and showing the bottom of the mold in cross-section.

Referring now to the drawings and more especially to Figures 1 and 2 thereof, the section of the mold 1 is that of a mold having substantially a rectangular shaped matrix in cross-section and with the bottom 4 of the mold comprising substantially a plane surface. This surface may be obtained in several ways such as machining, chipping or grinding but preferably is obtained by careful casting of the mold. in the form illustrated in Figures 1 and 2 projections 5 are cast adjacent the bottom of the mold and preferably integral therewith. The bottom corners or edges of these projections are definitely positioned from the axis of the mold in order to comprise guiding members.

The stool adapted to cooperate with this mold shown in Fig. 1 comprises a relatively fiat large casting having guiding ears 6 which, in the preferred form, extend upwardly and out ardly to provide guide surfaces 7 adapted to cooperate with the ears 6 to accurately center the bottom of the mold relative to the stool. In the form illustrated in Figs. 1 and 2 a small annular shelf or shoulder 8 is provided adjacent the joint of the mold with the stool and the central part of the stool is cupped. This cup 2 in the stool forms an extension on the end of the ingot cast therein whereby undesirable dendritic crystallization is obviated, and the annular shelf or shoulder8 between the mouth of the cup 2 and the lower inner corner of the mold prevents hot molten steel from burning out the sharp corner of the mold which sets tightly upon the stool to form a metal to metal joint and thereby obviates any formation of tins between the stool and the mold without the necessity of using any luting material. In this type of mold the centering of the mold on the stool so that the axis of the matrix of the mold is substantially coincident with the renter of the cup 2, is particularly important because in order to obtain the best results it is desirable that the shoulder 8 sha uniform Width entirely around the the bottom of the matrix of the nan-.4. and furthermore in the continued use mold there is :1 tends *l coming worn and u teat and unless s accurat i precedii has formi The outer level than provide an new which the mold as other parts i. formed castin.

stool against" an accurately formed chill plate. This produces a chilled surface havmg a close grain and with the n1a or portion of the free carbon in spheroidal form of the set-up.

The constructions disclosed in Figs. 1 and 2, therefore, provide a mold set-u in which an accurate metal to metal tight oint is automatically formed between the stool and the mold and is maintained throughout the life of the mold for the reason that the guiding projections on the mold and the guiding ears on the stool always center the mold properly over the stool for each mold set-up. This prevents the setting of the mold over any part of the stool which has beensubjected to hot metal and which may have been eaten away or eroded by contact with the hot metal. This construction also obviates the lifting of the mold from a proper seat upon the stool in view to any accidental setting of the mold upon scrutl', or other deleterious material which may tend to build up some part of the stool which has been in contact with hot metal. 1f the mold is set upon such a portion of a stool it opens the joint between the mold and stool at other points, where the scruil' may not be so thick, and the obvious result is an undesirable fin on the end of the ingot.

Figure 3 illustrates a construction whereby the mold side walls as at 11 are the guides which cooperate with the guiding ears on the stoe In the construction disclosed in Fig. 3 the central portion of the stool is indicated as being substantially flat but it will be observed that the relation of the bottom of the mold to the stool. maintained because of the guiding ears (5, is such that the mold alwayssets upon the same annular raised portion of the platform It), at each set-up, and therefore any irregularities that mav form in that pertion of the stool comprising a part of the matrix of the mold is always positioned within the and never under that part on which told sets.

a1 and 5 illustrate a construction in which the bottom of the mold is provided with tour diametrically oppo disposed guide lugs 26 and the stool pro. .ed wi h tour 31 rs of guid' T. 32%. and all t1 inclined s 353 thereon losed both el and of having a .lustrated. and the matter setting of the mold upon the stool more important in connection ltlt) with the recessed stool than it is with the plane stool, with the exception that in all cases it is a prime object of the present in-- size will always cooperate together withassurance that the mold will occupy exactly the same position on the stool as t at occupied by the preceding mold. Under these conditions the seating area on the stool is always a constant predetermined area and the matrix portion of the stool is always the same for each succeeding set-up.

Having thus described my invention, what I claim is:

1. The combination of an open-bottom ingot mold for casting steel ingots and a stool for said mold, said mold having a substantially plane bottom, guiding lugs upon said mold adjacentthe bottom thereof, said stool having a substantially plane seat for said mold whereby a ,close metal to metal joint is formed between said mold and said stool, and guiding means cooperating with the lugs on said mold to definitely positionsaid mold on the seat on said stool.

2. The combination of an ingot mold for steel ingots, a stool provided with a mold seat upon which said" mold is adapted to set, and inclined guiding means spaced apart from the mold seat to automatically and definitely position said mold on said stool during the lowering of said mold in position upon said stool, there being spaces intervening the mold and the stool between the base of the guiding means and the mold seat.

3. Incombination, a vertical mold for steel ingots having substantially a plane bottom, and a stool upon which said mold is adapted to set to form a metal to metal joint and with a portion of the stool form ing the lower matrix wall for the mold, said stool being formed of cast iron and having a chilled surface adapted to comprise saidmatrix wall.

4. In combination, a vertical open-bottom mold for steel ingots having subtantiall'y a plane bottom and a stool upon which said mold is adapted to set to form a metal to metal joint and with a portion of the stool forming the lower matrix wall for the mold, said stool being formed of cast iron and having a chilled surface adapted to comprise said matrix wall, and means to definitely position said mold upon said stool.

5. The combination of a vertical ingot mold for steel. and having a plane open-bottom, a cast iron stool provided with a raised seat adapted to cooperate with the bottom of said mold to form a close metal to metal joint, said seat upon said stool comprising a chilled cast iron surface.

6. As an article of manufacture, the cast iron ingot mold for manufacturing steelingots comprisin a substantially open tubular body with t e bottom substantially plane, and guiding lugs upon said mold adjacent the bottom thereof.

7. As an article of manufacture, a stool for ingot molds and having a work surface thereon of close grained metal with the maj or portion of the free carbon thereof in substantially spheroidal form adjacent said Work surface v 8. As an article of manufacture, a stool for ingot molds comprising a cast iron body portion having a substantially plane raised platform comprising a seat for suitable open-ended ingot molds and mold guiding means adjacent said seat.

9. The combination of an open botto ingot mold for steel ingots, a stool provided with a mold seat adapted to form a tight metal to metal joint with said mold, said stool being provided with a cup of less diameterthan the matrix. of the mold at the bottom of the mold to comprise a shoulder between the bottom of the mold and the mouthof the cup, and guiding means to cause said mold to rest upon the same portion of the mold seat for each mold and the stool.

JOHN E. PERRY.

set-up of the Y 

